In-situ measurement of manufacturing process parameters has been developing in recent years. While details of designs may vary, depending on the need of the specific applications, the central idea of the various design is to integrate structurally a sensing element of a certain shape, such as a pin, cone, or wedge, onto a tool-interface such that the sensing element is in contact with metallic or other material being processed. Prior designs are applicable to a conventional rolling process, for example, where rolls in a conventional rolling process have diameters in the range of 600 to 1,400 mm.
In contrast, a micro-rolling process involves forming rolls with diameters in the range of 28 to 66 mm. The more than ten-fold decrease in the diameter of the roll leads to a drastic decrease in volume available for sensor and sensing element integration, and precludes the employment of certain sensing techniques, such as those used in conventional rolling processes. In addition, high accuracy demanded for micro-rolling prohibits use of conventional sensors that require contact with a workpiece, such as sheet metal, as any contact reduces dimensional accuracy of a product produced from the workpiece and may even damage a formed texture on the product.